The story details the impassioned affair between openly gay banker, Daniel (Thomas Price) and the closeted, drug-addled lifeguard Kafka (Byron Pang). The young men fall in love, believing that their love can bridge anything, despite their difference in sexuality and Kafka's drug-taking. Daniel does not regret his love for Kafka, who tries to love him back against his nature. But a flashback memory from Kafka's past makes it difficult for their relationship to work. It turns out that their addiction to love proves more fatal than the drugs they use to explore the boundaries of their friendship.
The film stars Hong Kong Chinese actor and former model Byron Pang (Cantonese: Pang Koon-Kei) and Thomas Price, a half Chinese/half British actor who appeared in Permanent Residence and City Without Baseball. Like Scud's previous films, Permanent Residence (made in 2009) and the earlier City Without Baseball (2008), AMPHETAMINE features full-frontal male nudity in many scenes, in among others, an outdoor fight scene in which Pang is stripped naked by other boys, gym showers, and a leap from a public building, in which Pang wears 'wings', and his whole body is covered in calligraphy and silver paint.